The prior art is already aware of arrangements of material handling buckets which are under the control of fluid actuated apparatus, such as hydraulic cylinders. One isolated example of the arrangement in a backhoe is found in U.S. Pat. No. 3,220,579. It is the common practice in the prior art to have only one cylinder assembly for actuating a material handling bucket. Thus it is inherent in that arrangement that the bucket is moved with a certain force and at a certain speed, both consequences being determined by the capabilities of the fluid system and of the one cylinder itself.
The present invention utilizes two fluid cylinders for actuating the bucket, and the use of two cylinders is more efficient and less expensive than the use of a single cylinder assembly. Further, the arrangement of two cylinder assemblies in the present invention permits a forceful action on the bucket and it also permits a fast action on the bucket. That is, both cylinders can be pressurized when a forceful action is desired, such as when loading the bucket, and only one of the two cylinders can be pressurized, when a fast action is desired such as for emptying the bucket. Accordingly, the present invention provides a material handling bucket dual cylinder system which permits and utilizes the full fluid power available for maximum forceful actions when desired, and it also permits and utilizes a fast fluid power action when that is desired such as in the dumping or cleaning or like maneuvering of the bucket. Further, the present invention accomplishes the aforementioned objectives with a minimum of apparatus and without complex valves and complex apparatus, and the apparatus is therefore efficient and reliable and easy to operate so that the desired forceful or fast maneuverings can be accomplished.
Other objects and advantages will become apparent upon reading the following description in light of the accompanying drawings.